1. Field of the Invention
The invention relates to an active-matrix display device using light emitting elements in pixels. More particularly, the invention relates to a circuit configuration of a pixel including a sampling transistor, a driving transistor, and further a storage capacitor in addition to the light emitting element. Further particularly, the invention relates to a technology of improving write gain at the time of sampling a video signal in the storage capacitor. The invention also relates to electronic equipment in which such display device is incorporated therein.
2. Description of the Related Art
A planar self-light emitting display device using an organic EL device as the light emitting element has been extensively developed in recent years. The organic EL device is a device utilizing a phenomenon that an organic thin-film emits light when electric field is applied. Since the organic EL device is driven when an applied voltage is 10V or less, power consumption is low. In addition, since the organic EL device is a self-light emitting element which emits light by itself, lighting member is not necessary, as a result, it is easy to allow the device to be light and thin. Furthermore, since response speed of the organic EL device is extremely high such as approximately several μs, after-image at the time of displaying moving pictures does not occur.
Among the planar self-light emitting display devices using the organic EL devices in pixels, an active-matrix display device in which a thin-film transistor is formed at each pixel with integration as a driving element has been developed more extensively. The active-matrix planar self-light emitting display device is disclosed in, for example, JP-A-2003-255856, JP-A-2003-271095, JP-A-2004-133240, JP-A-2004-029791 and JP-A-2004-093682 (Patent Documents 1 to 5).